Heat exchanger



Aug. 30, 1927. 1,640,746

C. F. BRAUN HEAT EXCHANGER Filed March 14, 1922 Y 2 Sheets-Sheet llrrozw:

7 c. F. BRAUN HEAT EXCHANGER Filed March 14, 1922 Inyenior Byflarl I.Bra/21 2 cflahorneya v Patented Aug. 30, 1927.

CARL F. BRAUN, OF SAN FRANCISCO, CALIFORNIA.

HEAT EXCHANGER.

Application filed March 14, 1922. Serial No. 543,585.

This invention relates to heat exchanging apparatus, such as condensers,dephlegmators, and the like.

In bringing about an exchange of heat from one fluid to another as, forexample,

when a fluid is to be cooled or in some instances condensed as whenfluids are circulated in counter-directions through the particularpassageways of a multi-pass heat exchanger, objectionable conduction ofheat takes place between the passageways, whereby the cooling fluid mayto an objectionable extent be reheated as it reaches its point ofeduction.

It is the principal object of the present invention, therefore, toprevent the undesirable transmission of heat from one fluid to anotheras they flow along parallel passageways, thus insuring that a fluid maybe condensed and at the same time its condensate may also be cooled asthe circulation is carried on and that a desired progressive transfer ofheat may take place between the fluids.

The present invention contemplates the use of a plurality of exchangerunits, through which counterflows of fluid may be brought about andcontrolled to permit the fluids to circulate through a desired number ofunits thereby making it possible to reduce the temperature of the fluidto be cooled to an accurate determined degree.

The invention is illustrated b way of example in'the accompanyingrawings, in which:

Fig. 1 is a view in plan showing an assembled heat exchanger and moreparticularly disclosing the relative positions of the flow pipes.

Fig. 2 is a view in side elevation showing a pair of heat exchangersforming a part of the heatexchanger installation with which the presentinvention is concerned, one of said heat exchangers being shown incentral vertical section.

Fig. 3 is a View in end elevation showing the heat exchangers disclosedin Fig. 2, and

more particularly disclosing the flow pipe and valve arrangement.

Fig. 4 is a fragmentary view in transverse section through one of theheat exchanger, units, showing a particular form of longitudinalpartition wall. I

Fig. 5 is a transverse sectional View on the line 5-5 of Fig. 9.

a three-way by-pass Fig. 6 is a fragmentary view in section showlng aform of insulated partition wall.

Fig. 7 1s a transverse sectional view on the line 77 of Fig. '9.

Fig. 8 is a detail longitudinal sectional View on the line 8-8 of Fig.l.

Fig. is a fragmentary view in longitudi- 11211560131011 showing a formof the invention in which the longitudinal partition is in sections.

Referring more particularly to the drawmgs, 10 indicates a condenserinstallation, particularly adapted for use in refining oil. In Figs. 2and 3 it will be seen that this installation comprises a plurality ofsuper posed parallel condensers 12. These condensers are preferablydisposed with their forward ends in vertical alignment and with inletand outlet passageways systematically arranged at opposite sides of thecondensers.

Each of the I condensers is intended to accommodate counter currents ofcirculating fluids, as, for example, vapor maybe supplied through apipe13 and oil delivered through a pipe 14. These fluids may pass inseries through the several condensers, entering induction conduits l5and leaving the condensers through eduction conduits 16. The boltingflanges of like induction and eduction conduits are superposed and liein a single vertical plane, thus making it possible to supply each ofthe conduits with valve 17. By this ar-- rangement it is possible toquickly control the circulation of fluid through any or all of thecondensers so that a desired exchange of heat may be effected in each ofthe condensers.

It is to be understood that the fluid delivered to the condenser unit byconduit 13 may be carried away by a conduit 13, while the fluiddelivered to the unit by conduit 14' may be carried away by conduit 14.

he circulation of one fluid takes place along parallel passageways 18and 19 of each condenser, as, for example, the fluid from pipe 13 maypass into the shell, thereafter traveling along passageway 18, above alongitudinal partition wall 20, then passing around the end of this walland returning to the eduction conduit 13 along passageway 19. At thesame time a counter flow of another fluid is brought about through tubes21 extending longitudinally of the lower passageway 19, after which theflow of this fluid is continued through tubes 22 extendinglongitudinally of the upper passageway 18. The relative velocities offlow of the two fluids may be readily regulated by the various valves 17associated with each of the condensers.

Tn vapor condensers of the type shown in the drawing, an outer shell 23is provided and is divided longitudinally by a partition wall 20. Asshown in Fig. 2 of the drawing, this partition comprises a single sheetof material extending substantially the length of the shell, asindicated at 20. By refer ence to Figs. 5 and 7 of the drawing anotherform of partition wall will be found, comprising a plurality ofpartition members 25. These members are interposed between transversebaflie plates 26 and are secured in position by stay bolts 27. Thesebolts extend longitudinally of the shell through the transverse bafileplates and the interposed partition members. A tightjoint is madebetween the edges of the partition members contiguous to the inner faceof the shell by the formation of diametrically opposite key-ways 28 outthroughout the length of the shell, which key-ways receive splines 29projecting'from the opposite edges of the partition members and into thekey-ways. The splines are carried by grooves 30 formed along the edgesof the partition members. In the structure shown in Fig. 4 the oppositeedges of the continuous partition 20 projeets into the key-ways 28 toproduce the joint. In either structure it is thus possible to readilywithdraw the tube nest in its assembled condition if desired, and at thesame time to insure that whenthe tube nest,

transverse bafile plates and longitudinal partition wall are positionedwithin the shell two parallel passageways 18 and 19 will be formed.

In order to create a desired turbulence of the fluid passing through theshell the trans verse bafile plates 26 have been provided. The portionsof the baflie plates extending above the longitudinal partition arealternately formed, one with its marginal edge cut away to provide asubstantially semicircular opening 34 between this edge and the upperhalf of the shell wall, while the intermediate baffle plates are formedwith an approximately central opening 35 above the longitudinalpartition. By this arrangement the fluid circulating along passageway 18may be caused to alternately flow along and across the tubes 22 towardthe central opening 35 of one bafl'le plate, and then outwardly andaround the semicircular marginal edge of the next succeeding baflleplate. This will create turbulence throughout the length of thepassageway and around the tubes, while requiring a very simple andinexpensive baffle plate structure.

quantity of condensate between the baiile plates and on the floor formedby the longitudinal partition and the lower portion of the shell. Inorder to do this the openings formed in the baflle plates for thecirculation of fluid through the shell do not extend to the bottoms ofthe respective passageways but terminate a distance above the floor andthus provide riflles indicated at 38. It will be evident that theriilles which are above the floors will retard the flow of thecondensate longitudinally of the shell and will create a body ofcondensate between the baflle plates and on the floors of thepassagewavs. for the impounded condensate, at the same time permittingany excessive amount of condensate to flow through the openings 37. Thisbaffle construction also makes it possible. to progressively cool thecondensate as it passes through the condenser, due to the'fact that theaccumulated condensate will flow along the floors of the passageways inThe riffles 38 will establish a level mum low temperature and after ithas passed in counter direction along the cooling pipes. This conditionwill. however. tend to again raise the temperature of the fluid as itreaches the eduction passageway, thus to a certain extent counteractingthe cooling action which has already taken place.

For this reason it is contemplated to pass the fluid to be cooledsuccessively through a series of condensers, thereby confining thetemperature dlflerences of the influent and effluent fluid to a narrowlimit of range. v

This will not only insure an eflicient heat transfer but will alsoprevent undue strains in the metal of the condenser structure, asordinarily the temperature variations along the opposite sides of thelongitudinal partition will vary considerably. Further heat transferfrom one passageway to the other may be limited by covering the oppositesides of the longitudinal partition member shown in the drawings,

as shown in ing all of their stems parallel -with heatinsulatingmaterial or otherwise v incorporating heat insulating materialin the partition,'in which case it may be desirable to form the baffleplates 26 in two halves, as shown in Fig. i. These halves may be securedto opposite sides of a longitudinal partition member 20 and a thicknessof heat insulating material may be interposed. between the baflie platesand along the partition wall, as indicated at 24'.

In arranging the heat exchangers in series Fig. 2 the operation of theexchangers is greatly facilitated by the provision of the three-wayby-pass valves havand their operating wheels in single or parallelplanes at the ends of the exchangers. These valves will make it possiblefor the frictional drop of the circulating fluids to be regulated andalso the temperature in' each exchanger which in some heat exchangers,such as frac tionating condensers, is desirable. The provision ofby-pass valves also makes it possible for the individual heat exchangersto be cut out from the flow to permit them to be inspected, cleaned andrepaired.

Attention is directed to the fact that in the transverse sections of thecondensers here shown the baffle plates are firmly secured around thetubes which extend through them. In practice, it has been found thatthis will insure a more thorough transfer of heat from one fluid to theother, and will thus produce a more eflicient cooling action.

By referring to Figs. 4 and 6 it will be seen that partition members areprovided which tend to eliminate the transfer of heat from one side ofthe partition wall to theother. In Fig. 4: suitable insulating materialis embodied in the partition wall. However, in Fig. 6 the well knowninsulating properties of a fluid are employed, such as an interveningair space, which will tend to prevent the heat from being transferredfrom one spaced plate of the partition through the other.

' In operation, the plant is constructed as where it will be seen that aplurality of condensers is used. These condensers are connected tooperate in series as controlled by the valves 17.

Due to the relatively small temperature difierences between influent andefliuent tem ertures in the several exchangers, strains will be greatlyrelieved in the structures and.

at the same time it will be insured that heat transfer willprogressively take place without material intermittent retardation asthe cooled fluid reaches the induction ports of the series ofexchangers, and, furthermore,

the condensate may be progressively cooled as it flows through theshell.

It will thus disclosed insures an eflicient heat transfer from one fluidto another, while utilizing a be seen that the invention here throughthe tube nest.

convenient and readily controlled apparatus for bringing about theresult.

While I have shown the preferred form of my invention as now known tome, it will be understood that various changes might be made in thecombination, construction and arrangement of parts by those skilled inthe art, without departing from'the spirit of my invention, as claimed.7

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. In a heat exchanger, a shell, a longitudinally extending tube nestunit comprising a plurality of parallel tubes, means for sepalonglongitudinal passageways, and means for creating a tight joint betweenthe separating means and the shell, while permitting the tube nest unitto be removably secured within said shell.

2. A heat exchanger comprising an outer tubular shell, a plurality oftransverse baiiie plates disposed within said shell, partition membersinterposed between the bafiie plates and dividing the shell into a.plurality of circulating passageways which communicate with each otherat one end of the shell, a plurality of tubes extending lengthwise ofthe shell and through said baffle plates, and means for creating a flowof fluid alternately around the marginal edge of one upper passagebaflie plate and through a central opening in the next succeeding plate,while creating a flow in the lower passageway alternately around oneside of one bafiie plate and the opposite side of the next succeedingwith each other at oneend of the shell, and

a plurality of tubes extending lengthwise of I through the bathe theshell and passing plates, said bafiie plates being providedalternatelynear their centers and at their peripheries with openings for creating aflow of fluid alternately around the marginal edge of one baflie plateand through a central opening in the next succeeding baffle plate.

4. In a heat exchanger a tubular shell, 'a tube nest extendinglongitudinally thereof and enclosed thereby, a heat insulating partitionstructure extending longitudinally of the tube nest separating the tubesinto groups and dividing the shell into parallel passageways throughwhich a fluid may flow in counter current to the fiuid passing CARL F.BVRAUN.

